Electrical wiring connector block

ABSTRACT

An improved electrical wiring connector block in which the terminal lugs are preassembled at the factory, the blocks having knoblike protrusions formed thereon shaped and located to serve as anvils for crimping the lug ends on electrical conductors inserted therein, one or more connector blocks then being inserted into an associated housing wherein matching lug contacts of the blocks are aligned for electrical contact with each other, with contact strips in the housing, or with terminal strips of a printed circuit board inserted in the housing.

United States Patent 3,299,392 1/1967 3,409,857 11/1968 ONeil1eta1....3,461,258 8/1969 Shlesinger....................

DanielEppler Toms River, NJ. [21] AppLNo. 814,349

Apr. 8, 1969 Oct. 5, 1971 [72] Inventor [22] Filed FOREIGN PATENTS643,628 9/1950 GreatBritain................

4s Patented 3 39/ 198.2 1,144,663 3/1969 Great Britain....... 339/75(MP) Primary Examiner Marvin A. Champion Assistant Examiner-Lawrence J.Staab Attorney-Thomas M. Marshall [73] Assignee Thomas & BettsCorporation Elizabeth, NJ.

[54] ELECTRICAL WIRING CONNECTOR BLOCK 10 Claims, 5 Drawing Figs.

3,157,448 11/1964 Crimrninsetal... H housing.

PATENTEU mm 5 lsn SHEET 1 [1F 2 INVENTOR. DAN/E L EPPI. ER

. 4 T 7' ORNEYS PATENTEU mm 5 I97! 3,611,270

' sum 2 OF 2 INVENTOR. DAN/El. [PPLER Arm usys ELECTRICAL WIRINGCONNECTOR BLOCK This invention relates to improvements in electricalwiring connector blocks of the molded plastic type having a plurality oftransverse cavities adapted to receive metal crimp-type terminal lugsand to molded plastic housings for holding these blocks after they havebeen assembled with terminal lugs and wires.

More particularly, this invention relates to connector blocks in whichthe terminal lugs are preassembled at the factory. These connectorblocks have specially designed lug cavities which securely hold theterminal lugs in properly spaced relation, electrically insulated fromeach other, and also serve as novel anvil portions of lug crimping dies.

The connector blocks are adapted to be placed in a sliding traycompression tool, more fully described in my copending application, Ser.No. 814,348, filed Apr. 8, 1969, so that the lugs may be crimped abouttheir respective electrical conductors without removal from theconnector block.

Heretofore, it has been the practice to crimp each terminal lug aboutits conductor separately, using a plierlike crimping tool, and then toassemble it in the connector block. This procedure has severaldisadvantages. First, it is awkward for the operator to manipulate thelug, the wire conductor, and the crimping tool in proper relation to oneanother. Secondly, in holding the lug in his hand, the operator may getfingerprints on it which will subsequently cause surface corrosion withconsequent increased surface resistance. This is particularlydisadvantageous with spring-type terminal lugs which depend upon thepressure between mating tongues of the spring loops to provide goodcontact for the efiicient transfer of electrical current.

A third disadvantage is that the lugs may become twisted, bent or evenbroken when installed in the connector block by hand. The lugs must thenbe removed from their conductors and replaced. More seriously, if damageto a lug is not detected, improper contact may result in latermalfunction or failure of the equipment in which the connector block isinstalled.

Finally, the two-stage operation of first crimping each lug on its wireconductor and then installing the lug in the connector block is timeconsuming and requires trained operators.

By providing connector blocks preassembled with connector lugs underfactory controlled conditions and which are designed for crimping thelugs on their respective conductors while mounted in the block, myinvention overcomes all the aforementioned disadvantages. Factorypreassembly avoids the dual problems of corrosion and damage to the lugsand, because the connector block is designed to mount in the slidingtray fixture of a plier-type manual compression tool, the operator willhave his other hand free to guide the conductor wires into their properlugs. The task of preparing a completely wired connector block is thusaccomplished simply and rapidly.

After positioning one of my connector blocks in the sliding tray of sucha tool, the operator merely inserts a conductor wire in the crimping endof the first lug and squeezes the handles together to effect the crimpedconnection. Upon release of the handles, the tray automatically stepsone space over, ready to crimp the next lug. By continuing to insertconductors and squeeze the handles, the operator quickly completes theconnector block wiring operation without once having to touch the lugs.As mentioned earlier, the structure and sequence of operation of such asliding tray compression tool is more fully explained in my copendingapplication Ser. No. 814,348, filed Apr. 8, I969, entitled COMPRESSIONTOOL FOR ELECTRICAL CONNECTORS.

Accordingly, it is an object of this invention to provide a connectorblock of novel design in which the connector lugs are preassembled atthe factory.

It is another object of this invention to provide a connector block inwhich the lugs may be inserted by machine and held securely withoutscrews or rivets, yet be capable of manual replacement in the fieldshould the need arise.

It is further object of this invention to provide a connector blockwherein the lug cavity comprises the anvil portion of a lug crimping dieso that the preassembled lugs may be firmly crimped onto electricalconductors while in place in the connector block.

It is a further object of this invention to provide a connector blockhousing adapted to slidably receive connector blocks for effectingelectrical contact between the lugs of one connector block and matinglugs of another connector block or mating contact strips positionedwithin the housing or fastened to the edge of a printed circuit boardinserted therein.

These and other objects of the invention will become apparent from thefollowing description taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a cutaway perspective view of a connector block showing onelug assembled into position ready to receive a wire conductor.

FIG. 2 is a perspective view of a connector block mounted v in a slidingtray compression tool.

. FIG. 3 is a cutaway perspective view of a connector block housingadapted for use with a printed circuit board.

FIG. 4 is a sectional end view of an alternate form of connector blockhousing.

FIG. 5 is a sectional end view of another alternate form of connectorblock housing.

In these figures the same parts are identified by the same referencenumeral in each figure.

Referring to FIG. I, the connector block, designated generally bynumeral 1, is an elongated, generally rectangular. one-piece plasticmolding. The plastic should be relatively hard and strong with goodelectrical insulating properties. I prefer ABS plastic or glass-filledplastic, but suitable equivalents may also be used.

Connector block 1 has a flat rectangular base 2 on which is mounted aplurality of transverse, equally spaced partitions 3 to form transverselug-receiving cavities 4. A side yoke 5 and a center yoke 6 extendlongitudinally across the tops of trans verse partitions 3 along oneside and generally down the center, respectively, of the connectorblock. The portion of each lug receiving cavity 4 between the two yokes5 and 6, is designated the crimping cavity 7.

Important features of the invention are convex knoblike protrusions 8,integrally molded on base 1 within each crimping cavity 7. Theseprotrusions serve the dual functions of locking the lugs in placeagainst lateral forces tending to slide them out of lug cavities 4 andof providing a crimping anvil to permit crimping the lugs on theirrespective electrical conductors, as will be more fully explained below.If the blocks are molded of ABS plastic or glass-filled plastic,protrusions 8 will be hard enough to serve satisfactorily as anvils inthe lug crimping process. Alternatively, a softer plastic may be usedand the knob surfaces hardened by metallic plating.

At each end of connector block 1, extensions of base 2 act as locatingshoulders 9 for properly positioning the block in a connector blockhousing.

A terminal lug 10 is shown in position in one of the lug cavities 4, itbeing understood that the connector block is supplied from the factorywith lugs preassembled in every lug cavity. The lugs are formed from astrip of malleable conductive metal, such as copper, and normally have abright finish to provide good electrical contact. Each lug has acrimping portion 11 and a spring contact portion 12. At the other end ofthe crimping portion are two upstanding ears 13 which serve to hold thelug securely within the opening formed by partitions 3 and side yoke 5.Next to upstanding ears 13 are crimping ears 14 located on that part ofthe lug which is positioned over protrusion 8. As is shown by thecutaway section of FIGURE 1, the crimping portion of lug I0 is bentupwardly to conform to the shape of protrusion 8.

Spring contact portion 12 of the lug consists of a flat recurvingtongue, the end of which fits under and presses up against center yoke6. The recurving tongue acts as a leaf spring; so it can be depressed toallow insertion of the lug, first under side yoke 5 and then undercenter yoke 6. When the lug is fully inserted in cavity 4, the springaction of the recurving tongue pressing against yoke 6 together withupstanding ears 13 pressing against yoke 5 combine with protrusion 8 toprovide a detent effect which locks the lug against forces tending topush it further through the cavity or to pull it back out. In thismanner, the lug is held firmly within the cavity without screws orrivets; yet it can be easily removed, if necessary, by depressing thespring contact portion 12 and pulling the lug out under center yoke 6and side yoke 5.

The preferred form of protrusions 8 is a convex oval shape, as isindicated in FIG. 1. Such a form may be described as one portion of anellipsoid which has been divided by a plane parallel to its axis ofrevolution. In this case the plane is represented by base 2 of theconnector block. The intersections of the base with the surfaces ofthese ellipsoids are ellipses whose major axes coincide with thecenterline of each lug receiving cavity 4. The minor axes of theellipses coincide with a line parallel to the longitudinal edge of base2 and spaced approximately midway between side yoke 5 and center yoke 6.

The ellipsoidal form of protrusions 8 has several advantages. Thegradual slope along the major axis permits smooth insertion of the lugsinto the cavities, an important factor in reducing the number of rejectsdue to broken or twisted lugs in an automated assembly operation. At thesame time, the appreciable transverse extent of such an ellipsoidalprotrusion produces, in conjunction with ears 13 and the recurvingtongue of spring portion 12, an improved locking effect against the lugsbeing pushed or pulled out of position. That is, a protrusion shapewhich is relatively long in the direction transverse of the blockprovides less opportunity for the inherent flexibility of the lug topermit relatively small forces to push or pull it out of the cavity.Furthermore, an ellipsoidal shape efiectively distributes the downwardforces encountered during the crimping process so as to preventcrushing, cracking or spalling of the plastic block.

My invention is not limited, however, to an ellipsoidal form forprotrusions 8 but embraces equivalent shapes for the crimping cavityportion as would suggest themselves to one skilled in the art toaccomplish the same functions of securing the lugs without screws orrivets and of providing a crimping anvilv Referring to FIG. 2, aconnector block 1 is shown mounted in a sliding tray compression tool20, such as is the subject of my copending application Ser. No. 814,348,filed Apr. 8, I969.

The frame of compression tool 20 carries an L-head 21 in which ismounted a downward-facing crimping die 22. A movable jaw 23 reciprocateswithin the frame of tool 20 (by means not shown) toward and away fromcrimping die 22. A slotted base 24 is mounted in movable jaw 23 and, inturn, carries tray 25 for reciprocal sliding motion perpendicular to thedirection of reciprocation of jaw 23 under the crimping die 22.

To use the tool, the operator places a connector block in the slidingtray and slides the tray to position the lug in the first crimpingcavity 7 underneath the crimping die. Next, he places the end of anelectrical conductor 15, from which the insulation 16 has been stripped,between the crimping ears 14 of the connector lug 10. By operation ofthe reciprocating means, he then raises jaw 23 toward L-head 21 so thatears 14 are squeezed between crimping die 22 and protrusion 8 to effecta tight electrical and mechanical bond with conductor 15.

Upon release of the reciprocating means, jaw 23 moves away from L-head21, and an indexing mechanism, not shown, automatically permits thetension of spring 26 to cause tray 25 to slide one space so that thenext cavity is positioned under the crimping die. The operating sequenceis repeated until all lugs are crimped about their respectiveconductors.

It is apparent from the above description that by using my connectorblocks having specially designed retaining yokes, and anvillikeprotrusions in each crimping cavity, and equipped with factorypreassembled terminal lugs, an operator can produce completely wiredconnector blocks more easily and in less time than it formerly took tocrimp separate lugs onto their electrical conductors. Furthermore, thelugs are never touched by the operator, thus eliminating the problems ofcorrosion, distortion and misalignment.

Referring to FIG. 3, two connector blocks 30 are shown mounted in aspecial plastic connector housing 40.

Housing 40 is generally in the shape of a fiat, rectangular box, openalong one side. The spacing between top 41 and bottom 42 is sufficientto provide a sliding fit for two connector blocks 30 placed face-to-faceso that side yokes 5 are adjacent to each other. With the completelywired connector blocks held in this position, they can be easilyinserted into the connector housing past fingers 43 of latches 44 bylightly pressing the bases 2 together against the action of springcontacts l2. Latches 44 are able to yieldably spring outward by reasonof slits 45 cut transversely into the top and bottom of housing 40.

In the version shown in FIG. 3, the connector block housing 40 has twolatches 44 on both top 41 and bottom 42 which are aligned with connectorblock cantilever springs 31 and 32. These springs push outward againstfingers 43 when the blocks are latched into the housings, thus urgingthe opposite edges of the blocks against the beveled inside comers 46 ofthe housing. The lateral force of springs 31 and 32 against fingers 43causes bases 2 to ride up on beveled comers 46 to move spring contacts12 of opposite lugs in the two connector blocks together, so that thecontact surfaces will seal against each other to prevent dust andoxidation from increasing the surface resistance when there is noprinted circuit board inserted in the connector housing.

Along the center line of the side of housing 40 opposite to the openside is a narrow slot 47 adapted to receive the edge of a printedcircuit board 50 having contact surfaces 51 in spaced alignment withspring contacts 12 of the lugs mounted in the two connector blocks. Theprinted circuit board slides into slot 47 and between spring contacts12, which provides an electrical path from the conductors, through thelugs, to the individual contact surfaces 51 on the board 50. Beveledcorners 46 insure that there will be good electrical connection betweenspring contacts 12 and contact surfaces 51 regardless of variations inprinted circuit board thickness. Thicker boards, acting on springcontacts 12, will tend to push the connector blocks apart, but thismotion will be resisted by the force of springs 31 and 32 so that bases2 will reach an equilibrium position on beveled comers 46 for each boardthickness.

Referring to FIG. 4, an alternate form of connector block housing isshown for use as a junction box for connecting two sets of electricalconductors. In this version, two connector blocks are inserted fromopposite sides of housing 60. The height of each of the connector blockreceiving compartments 61 and 62 is designed to provide a snug fit tothe mating dimension between the bottom of base 2 and top of side yoke 5of each connector block 1. In addition, the two receiving compartments61 and 62 are offset from each other, not only to permit proper matingbetween spring contacts 12 but also to provide shoulders 63 and 64 whichact as stops for the connector blocks. Latches 65 and 66 act inconjunction with shoulders 63 and 64 to lock the blocks against lateralmotion inside housing 60.

FIG. 5 illustrates still another form of housing for use when it isdesired to hold two connector blocks carrying different electricalsignals. Housing 70 is similar in shape to housing 40 in FIG. 3, andboth connector blocks are similarly inserted from the same side.However, in housing 70 the blocks are placed base-to-base so that therewill be no electrical contact between their respective connector lugs.Instead, spring contacts 12 engage mating contact strips 71 and 72 whichare imbedded in the inside surfaces of the top 73 and bottom 74,respectively, of housing 70. The ends of strips 71 and 72 are led outthrough the top and bottom surfaces of sidewall 75 to suitable connectorfittings, either solder or crimp type.

The main portions of top 73 and bottom 74 of housing 70 are spaced apartto provide a sliding fit for the outer surfaces of center yokes 6 andpartitions 3 of the two connector blocks 1. The edges of top 73 andbottom 74 which abut the open side of housing 70 are reduced inthickness to form flexible latches 76 and 77. The reduced thickness notonly improves the flexibility of the latches but also provides internalclearance to accommodate side yokes 5 of the connector blocks 1.

To provide additional support and to insure that the pressure of springcontacts 12 is equalized against contact strips 71 and 72, ridges 78 and79 are molded along the inner surface of sidewall 75 and extendlaterally across each end of block 1. Ridges 78 and 79 are spacedsymmetrically about a horizontal plane through the center of block 70and are spaced to provide a sliding fit for the double thickness ofbases 2 and shoulders 9 (see FIG. 1) of the two connector blocks.

in order for the edges of bases 2 to slide between the longitudinallyextending portions of ridges 78 and 79, the connector blocks in FIG. 5have modified partitions 3 which extend only between side yokes 5 andcenter yokes 6. Because of the support of the side and center yokes inconjunction with the locking effect of protrusions 8, there is no dangerthat the lugs will becomeloose or short against one another by reason ofeliminating the portions of partitions 3 which extend transversely pastcenter yokes 6.

Having thus described the invention, it is not intended that it be solimited, as changes may be made therein without departing from the scopeof the invention. Accordingly, it is intended that the subject matterdescribed above and shown in the drawings be interpreted as illustrativeand not in a limiting sense.

lclaim:

l. in a plastic electrical connector block of the type having anelongated generally rectangular base with a plurality of equally spacedtransversely extending partitions molded thereon to form a series oftransverse lug receiving cavities, the improvement which comprises aplurality of protrusions formed on said base within each lug receivingcavity and located on a line parallel to one of the longitudinal sidesof said block, for serving as anvils upon which to crimp connector lugs,preassembled in said lug receiving cavities, about correspondingelectrical conductors, each of said protrusions being electroplated toprovide increased surface hardness whereby the effectiveness of saidprotrusions as crimping anvils is improved.

2. In a plastic electrical connector block of the type having anelongated generally rectangular base with a plurality of equally spacedtransversely extending partitions molded thereon to form a series oftransverse lug receiving cavities, the improvement which comprises aplurality of protrusions formed on said base within each lug receivingcavity and located on a line parallel to one of the longitudinal sidesof said block, for serving as anvils upon which to crimp connector lugs,preassembled in said lug receiving cavities, about correspondingelectrical conductors, each of said protrusions being in the form of aportion of an ellipsoid having its major axis aligned transversely ofsaid block.

3. In a plastic electrical connector block of the type having anelongated generally rectangular base with a plurality of equally spacedtransversely extending partitions molded thereon to form a series oftransverse lug receiving cavities, the improvement which comprises aplurality of protrusions formed on said base within each lug receivingcavity and located on a line parallel to one of the longitudinal sidesof said block, for serving as anvils upon which to crimp connector lugs,preassembled in said lug receiving cavities, about correspondingelectrical conductors, said connector block having a side yoke extendinglongitudinally across the tops of said transverse partitions along oneedge of the block and a center yoke extending parallel to and spacedfrom said side yoke, whereby a terminal lug may be securely held in eachof said lug receiving cavities without the need for separate fasteners.

4. An electrical connector block as defined in claim 3, in which saidprotrusions are located on a longitudinal line spaced between said sideyoke and said center yoke.

5. An electrical connector block housing assembly comprismg:

a. at least two elongated plastic electrical connector blocks, eachhaving: l a flat rectangular base with a plurality of spaced transversepartitions molded thereon for dividing the base into a series oftransverse lug receiving cavities, and (2) spring means formed on oneedge of the base thereof;

a plurality of malleable metallic terminal lugs removably secured bymolded retaining means in said lug receiving cavities, and each lughaving means at one end for making a mechanical and electricalconnection with an electrical conductor, and being formed with a springcontact portion at the other end; and a molded hollow rectangularplastic housing having: (1) at least one open side for slidablyreceiving said connector blocks, said connector blocks being oriented insaid housing so that said one end of each of the terminal lugs isadjacent said open side; (2) flexible latching means for removablysecuring said blocks to said housing; and (3) stop means disposed withinsaid housing, said spring means of the connector blocks cooperating withsaid flexible latching means to yieldably urge the opposite edges ofsaid connector block base against said stop means.

6. An electrical connector block housing assembly as defined in claim 5wherein said flexible latching means comprise integral portions of atleast one of the faces of said housing adjacent said open side andhaving finger portions extending in the way of said open side forreleasable engagement with said blocks when they are completely insertedin said housing.

7. An electrical connector block housing assembly as defined in claim 6wherein said housing is adapted to receive two connector blocks orientedso that the spring contact surfaces of the terminal lugs face each otherand includes a. an elongated opening in the side opposite said open sidefor receiving the edge of a printed circuit board, said board havingelectrical contact strips extending perpendicularly from said edge andspaced coincidentally with the spring contact surfaces of said terminallugs, whereby said strips will make electrical contact with the opposingspring contact surfaces of said terminal lugs when the board is insertedin said elongated opening and b. wedge means whereby the thrust of saidspring means against the fingers of said latching means tends to forcethe inner edges of the bases of said connector blocks together wherebythe opposing surfaces of said lug spring contact portions will makesealing contact when said printed circuit board is withdrawn from saidassembly.

8. An electrical connector block comprising a base having a plurality ofmutually spaced partitions formed thereon to define a series of lugreceiving cavities, with a protrusion formed on said base within eachlug receiving cavity and located on the longitudinal centerline thereoffor serving as an anvil upon which to crimp connector lugs, preassembledin said lug receiving cavities, about corresponding electricalconductors, said protrusions being in the form of a portion of anellipsoid and being electroplated to provide increased surface hardnesswhereby the effectiveness of said protrusions as crimping anvils isimproved.

9. An electrical connector block comprising a base havinga plurality ofmutually spaced partitions formed thereon to define a series of lugreceiving cavities, with a protrusion formed on said base within eachlug receiving cavity and located on the longitudinal centerline thereoffor serving as an anvil upon which to crimp connector lugs, preassembledin said lug receiving cavities, about corresponding electricalconductors, said electrical connector block having a first yokeextending longitudinally across the tops of said partitions along oneedge of the block, and a second yoke extending parallel to and spacedfrom said first yoke and also extending across the 10. An electricalconnector block as in claim 9 in which said tops of said partitions,whereby a terminal lug may be securely protrusions are located betweensaid first yoke and said held in each of said lug receiving cavitieswithout the need for second yoke.

separate fasteners.

1. In a plastic electrical connector block of the type having anelongated generally rectangular base with a plurality of equally spacedtransversely extending partitions molded thereon to form a series oftransverse lug receiving cavities, the improvement which comprises aplurality of protrusions formed on said base within each lug receivingcavity and located on a line parallel to one of the longitudinal sidesof said block, for serving as anvils upon which to crimp connector lugs,preassembled in said lug receiving cavities, about correspondingelectrical conductors, each of said protrusions being electroplated toprovide increased surface hardness whereby the effectiveness of saidprotrusions as crimping anvils is improved.
 2. In a plastic electricalconnector block of the type having an elongated generally rectangularbase with a plurality of equally spaced transversely extendingpartitions molded thereon to form a series of transverse lug receivingcavities, the improvement which comprises a plurality of protrusionsformed on said base within each lug receiving cavity and located on aline parallel to one of the longitudinal sides of said block, forserving as anvils upon which to crimp connector lugs, preassembled insaid lug receiving cavities, about corresponding electrical conductors,each of said protrusions being in the form of a portion of an ellipsoidhaving its major axis aligned transversely of said block.
 3. In aplastic electrical connector block of the type having an elongatedgenerally rectangular base with a plurality of equally spacedtransversely extending partitions molded thereon to form a series oftransverse lug receiving cavities, the improvement which comprises aplurality of protrusions formed on said base within each lug receivingcavity and located on a line parallel to one of the longitudinal sidesof said block, for serving as anvils upon which to crimp connector lugs,preassembled in said lug receiving cavities, about correspondingelectrical conductors, said connector block having a side yoke extendinglongitudinally across the tops of said transverse partitions along oneedge of the block and a center yoke extending parallel to and spacedfrom said side yoke, whereby a terminal lug may be securely held in eachof said lug receiving cavities without the need for separate fasteners.4. An electrical connector block as defined in claim 3, in which saidprotrusions are located on a longitudinal line spaced between said sideyoke and said center yoke.
 5. An electrical connector block housingassembly comprising: a. at least two elongated plastic electricalconnector blocks, each having: (1) a flat rectangular base with aplurality of spaced transverse partitions molded thereon for dividingthe base into a series of transverse lug receiving cavities, and (2)spring means formed on one edge of the base thereof; b. a plurality ofmalleable metallic terminal lugs removably secured by molded retainingmeans in said lug receiving cavities, and each lug having means at oneend for making a mechanical and electrical connection with an electricalconductor, and being formed with a spring contact portion at the otherend; and c. a molded hollow rectangular plastic housing having: (1) atleast one open side for slidably receiving said connector blocks, saidconnector blocks being oriented in said housing so that said one end ofeach of the terminal lugs is adjacent said open side; (2) flexiblelatching means for removably securing said blocks to said housing; and(3) stop means disposed within said housing, said spring means of theconnector blocks cooperating with said flexible latching means toyieldably urge the opposite edges of said connector block base againstsaid stop means.
 6. An electrical connector block housing assembly asdefined in claim 5 wherein said flexible latching means compriseintegral portions of at least one of the faces of said housing adjacentsaid open side and having finger portions extending in the way of saidopen side for releasable engagement with said blocks when they arecompletely inserted in said hoUsing.
 7. An electrical connector blockhousing assembly as defined in claim 6 wherein said housing is adaptedto receive two connector blocks oriented so that the spring contactsurfaces of the terminal lugs face each other and includes a. anelongated opening in the side opposite said open side for receiving theedge of a printed circuit board, said board having electrical contactstrips extending perpendicularly from said edge and spacedcoincidentally with the spring contact surfaces of said terminal lugs,whereby said strips will make electrical contact with the opposingspring contact surfaces of said terminal lugs when the board is insertedin said elongated opening and b. wedge means whereby the thrust of saidspring means against the fingers of said latching means tends to forcethe inner edges of the bases of said connector blocks together wherebythe opposing surfaces of said lug spring contact portions will makesealing contact when said printed circuit board is withdrawn from saidassembly.
 8. An electrical connector block comprising a base having aplurality of mutually spaced partitions formed thereon to define aseries of lug receiving cavities, with a protrusion formed on said basewithin each lug receiving cavity and located on the longitudinalcenterline thereof for serving as an anvil upon which to crimp connectorlugs, preassembled in said lug receiving cavities, about correspondingelectrical conductors, said protrusions being in the form of a portionof an ellipsoid and being electroplated to provide increased surfacehardness whereby the effectiveness of said protrusions as crimpinganvils is improved.
 9. An electrical connector block comprising a basehaving a plurality of mutually spaced partitions formed thereon todefine a series of lug receiving cavities, with a protrusion formed onsaid base within each lug receiving cavity and located on thelongitudinal centerline thereof for serving as an anvil upon which tocrimp connector lugs, preassembled in said lug receiving cavities, aboutcorresponding electrical conductors, said electrical connector blockhaving a first yoke extending longitudinally across the tops of saidpartitions along one edge of the block, and a second yoke extendingparallel to and spaced from said first yoke and also extending acrossthe tops of said partitions, whereby a terminal lug may be securely heldin each of said lug receiving cavities without the need for separatefasteners.
 10. An electrical connector block as in claim 9 in which saidprotrusions are located between said first yoke and said second yoke.